#include<stido.h>
#include<time.h>
#include<math.h>

long add1(long n)
{
    long i, sum = 0;
    for (i = 1;i < = n;i++)
      sum+=i;
    return sum;
}
void AddTime1(long n)
{
    clock_t t;
    long sum;
    t = clock();
    sum = add1(n);
    t = clock() - t;
    printf("方法1：\n");
    printf("  结果：1~%d之和:%1d\n",n,sum);
    printf("  用时: % 1f秒\n",((float)t)/CLOCKS_PER_SES);
}
long add2(long n)
{
    return n * (n+1)/2;

}
void AddTime2(long n)
{
    clock_t t;
    long sum;
    t = clock();
    sum = add1(n);
    t = clock() - t;
    printf("方法2：\n");
    printf("  结果：1~%d之和:%1d\n",n,sum);
    printf("  用时: % 1f秒\n",((float)t)/CLOCKS_PER_SES);
}
int main()
{
    int n;
    printf("n(大于1000000）:");
    scanf("% d",&n);
    if(n<1000000)
    return 0;
    AddTime1(n);
    AddTime2(n);
    return 1;

}